JP6789715B2 - Printing equipment - Google Patents

Description

The present invention relates to a printing device that prints on the surface of an object to be conveyed by the conveying device, and particularly for the object being conveyed even when the object being conveyed is displaced in a direction orthogonal to the conveying direction. The present invention relates to a printing apparatus capable of appropriately printing.

Conventionally, identification information such as a product name and a product number is displayed on the surface of tablets such as pharmaceuticals for the purpose of preventing erroneous administration and improving the distinctiveness when a pharmacist prescribes a drug. Then, as a method for displaying such identification information on a tablet, a printing method using a non-contact type automatic printing device as disclosed in, for example, Japanese Patent Application Laid-Open No. 7-81050 (Patent Document 1) has been used. Proposed.

This automatic printing device is provided above an aligning device that aligns objects such as tablets and capsules in a straight line, a supply conveyor that conveys the aligned objects, and an object on the supply conveyor. An inkjet printer having a detection device for detecting and a jet nozzle for ejecting ink from a tip portion and arranged directly above the supply conveyor on the downstream side in the transport direction from the detection device, and the like. It is configured to include a control unit that controls the operation.

Then, the control unit receives a detection signal when the detection device detects the object from the detection device, and the target object detects the object at a predetermined discharge timing based on the reception of the detection signal. It is configured to transmit a signal for ejecting ink to the inkjet printer at a timing when it reaches a position directly under the inkjet printer after a lapse of a predetermined time after being detected by the apparatus.

Thus, according to this automatic printing device, first, a plurality of objects are aligned in a straight line by the alignment device, and the aligned objects are conveyed by the supply conveyor along a predetermined transfer direction. Then, when the object to be conveyed on the supply conveyor is detected by the detection device and the detection signal is input to the control unit, the control unit determines the discharge timing based on the reception of the detection signal, that is, the target. When an object reaches a position directly below the inkjet printer, a signal for ejecting ink is transmitted to the inkjet printer. As a result, ink is ejected from the jet nozzle of the inkjet printer toward the object, and the identification information is printed on the object.

Japanese Unexamined Patent Publication No. 7-81050

By the way, the print position of the identification information printed on the surface of the object is usually set to the center position of the object. This is because if the identification information is printed at the center position of the object, the appearance is well-balanced and the viewer is given a sense of beauty.

Therefore, from such a viewpoint, in the automatic printing apparatus, as shown in FIG. 11, the path followed by the central CP of the object T'carried by the supply conveyor 102 when viewed from a plane is the path of the jet nozzle 101. It is necessary to be a path (set path) passing through the center point P, and when the path of the object T'is set in this way, the jet nozzle 101 is used to make the surface of each object T' The identification information can be printed with reference to the central CP. In FIG. 11, the arrow H'indicates the transport direction.

However, in the above-mentioned conventional automatic printing apparatus, in the design setting, the path followed by the center CP of the object T'carried by the supply conveyor 102 is the path passing through the center point P of the jet nozzle 101. However, in reality, the path followed by the center CP of the object T'is not necessarily the path (set path) that passes through the center point P of the jet nozzle 101 due to the influence of various disturbances. The reality is that it has not.

That is, in the automatic printing device, for example, when the object T'is transferred from the alignment device to the supply conveyor, the vibration generated in the alignment device and the vibration generated in the supply conveyor cause disturbances on the supply conveyor. The position of the object T'transferred to the object T'is misaligned with respect to the set position. Therefore, as shown in FIG. 12, the path followed by the central CP of the object T'is, for example, a jet nozzle. The position is displaced from the set path S passing through the center point P of 101 in a direction orthogonal to the transport direction H'by, for example, ΔX.

When the object T'is displaced from the set path S in the direction orthogonal to the transport direction H'in this way, it is printed on the surface of the object T'by the jet nozzle 101 as shown in FIG. The identification information will be displaced from the center CP of the object T'.

Then, when the identification information printed on the surface of the object is displaced from the center of the object in this way, it is conventionally excluded as a defective product due to the above-mentioned appearance problem and the like. When the number of defective products due to such printing problems increases, there is a problem that the yield is lowered due to the appearance problem even though there is no problem in the actual quality of the object. Therefore, conventionally, it has been desired to develop a printing device capable of printing identification information with reference to the center of the object even if the position of the object to be transported deviates from a predetermined set path.

The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a printing apparatus capable of printing information on the surface of an object to be transported with reference to the center position thereof.

As a reference aspect for the present invention for solving the above problems,
A transport mechanism that transports an object along a transport surface that includes a predetermined reference transport path,
An object detection mechanism that detects the object transported by the transfer mechanism,
A misalignment detection mechanism that detects a misalignment of the object from the reference transport path in the direction orthogonal to the reference transport path in the transport surface.
It is composed of a printing mechanism that prints on the surface of the object transported by the transport mechanism.
The misalignment detection mechanism
In the transport direction of the transport mechanism, it is arranged on the downstream side of the object detection mechanism, receives a detection signal from the target detection mechanism, and at a predetermined imaging timing with reference to the time when the detection signal is received. An imaging camera that captures the surface of an object detected by the object detection mechanism,
It is composed of a misalignment detection unit that processes an image captured by the imaging camera and detects the misalignment of the object from the reference transport path.
The printing mechanism
A printer head including a nozzle array in which a plurality of ink ejection nozzles are arranged at regular intervals, and the nozzle array is the reference transfer path on the downstream side of the imaging camera in the transfer direction with reference to the reference transfer path. A printer head that is arranged so as to be orthogonal to the above and forms a predetermined print area with reference to the reference transport path.
It consists of a printing unit that causes the printer head to perform printing operations.
The printing unit
A print data storage unit that stores print data for printing on the surface of the object and is composed of line data for at least one line in the raster direction assigned to each ink ejection nozzle.
The misalignment information detected by the misalignment detection unit is received, processing is started, the print data is sequentially read from the print data storage unit for each line, and the read line data is used from the misalignment detection unit. A shift processing unit that generates and outputs shift line data in which the allocation relationship to the ink ejection nozzle is shifted according to the position shift direction and the position shift amount based on the received position shift information.
The shift line data output from the shift processing unit is stored, the detection signal is received from the object detection mechanism, and the shift line data is sequentially output at a predetermined discharge timing based on the reception of the detection signal. Buffer part and
Receiving a shift line data outputted from the buffer unit, based on the shift line data received, Ru can be given printing device composed of a print control unit for operating the ink ejection nozzle corresponding.

In this aspect , the reference transport path is a transport path set by design, and is a path that the center position in the plan view of the object should follow, and is set along the transport direction in the transport surface. It is conceived as a reference line.

Further, the printer head is arranged so that a predetermined print area is formed on the surface of the object to be conveyed on the reference transfer path. The width of the print area in the direction orthogonal to the reference transport path (hereinafter referred to as the left-right direction) is set to be larger than the print width actually printed on the object (hereinafter referred to as the actual print width). There is. Therefore, the width of the print area has a margin width larger than the actual print width.

In the printing apparatus according to this aspect , a plurality of objects are sequentially conveyed along the conveying surface by the conveying mechanism. The transport mechanism has a reference transport path set in the transport surface, and the object is transported so that its center position follows the reference transport path in terms of setting.

The transported object is detected by the object detection mechanism, and the detection signal is transmitted from the object detection mechanism to the imaging camera. The imaging camera has an imaging field of view that images the surface of the transported object, receives a detection signal from the object detection mechanism, and has a predetermined imaging timing, that is, based on the time when the detection signal is received. The object is detected by the object detection mechanism, and the surface of the object is imaged at the timing when it enters the imaging field of view after a lapse of a predetermined time.

When an object is imaged by the imaging camera, the image data is processed by the position shift detection unit, and the position shift of the object based on the reference transport path, that is, the reference transport with respect to the reference transport path. The displacement of the object in the direction orthogonal to the path is detected. Here, for example, the misalignment detection unit processes the captured image to recognize the center position of the object, and how much the recognized center position is in any of the left-right directions with reference to the reference transport path. Information on how many pixels (for example, how many pixels) the position is displaced (positional deviation information) is calculated and transmitted to the shift processing unit.

The shift processing unit receives the position shift information from the position shift detection unit, starts processing, sequentially reads the print data from the print data storage unit for each line, and detects the position shift from the read line data. Based on the position shift information received from the unit, shift line data in which the allocation relationship to the ink ejection nozzle is shifted according to the position shift direction and the position shift amount is generated and stored in the buffer unit. Printing on an object is realized by combining a plurality of printing lines along the left-right direction. The line data is data for forming one printing line, and is a collection of dot data indicating ink ejection or non-ejection assigned to each ink ejection nozzle constituting the nozzle row. ..

For example, when the object is displaced to the right in the traveling direction by n pixels as print data, the shift processing unit shifts the line data read from the print data storage unit by this displacement. However, in order to shift the allocation relationship to the ink ejection nozzle, empty data for n pixels is added to the head portion of the line data to be read, and data for n pixels is deleted from the end. As a result, the allocation relationship of the print data to the ink ejection nozzle is shifted to the right by n pixels.

On the other hand, when the object is displaced to the left in the traveling direction by m pixels as print data, the shift processing unit shifts the line data read from the print data storage unit by the amount of this displacement. However, in order to shift the allocation relationship to the ink ejection nozzle, the data for m pixels is deleted from the beginning of the line data to be read, and the empty data for m pixels is added to the end of the line dataon. As a result, the allocation relationship of the print data to the ink ejection nozzle is shifted to the left by m pixels.

Subsequently, the shift line data is sequentially output to the print control unit by the buffer unit at a predetermined timing based on the reception of the detection signal from the object detection mechanism. Then, based on the received shift line data, the print control unit operates the corresponding ink ejection nozzle.

As described above, according to the printing apparatus according to this aspect , based on the misalignment information of the object detected by the misalignment detection unit, the shift processing unit ejects ink according to the misalignment direction and the misalignment amount. Shift line data in which the allocation relationship to the nozzles is shifted is generated, and the ink ejection nozzle is operated by the print control unit based on the shift line data. As a result, even when the object is transported in a direction orthogonal to the reference transport path with respect to the reference transport path, the allocation relationship of the print data to the ink ejection nozzle is the amount of the misalignment. By operating the ink ejection nozzle based on the shifted shift line data, it is possible to correct the line data before the shift process so that the print position becomes appropriate. Therefore, it is possible to appropriately print the print information on the surface of the object with the center position as a reference.

Further, in the above aspect , the printer head includes at least two rows of nozzles arranged side by side along the reference transport path, and each nozzle row constitutes an ink ejection nozzle. Is arranged so as to be displaced in a direction orthogonal to the reference transfer path with respect to each ink ejection nozzle constituting the other nozzle array and to be located between the ink ejection nozzles constituting the other nozzle array. It is configured so that the ink ejection nozzles of each nozzle row are located at regular intervals in the direction orthogonal to the reference transfer path as a whole.
The print data storage unit is configured to store print data composed of line data for at least one line in the raster direction assigned to each ink ejection nozzle constituting each nozzle row.
Based on the position shift information received from the position shift detection unit, the shift processing unit reads out the line data, and ejects each ink constituting each nozzle row according to the position shift direction and the position shift amount. It is configured to generate shift line data with a shifted allocation relationship for the entire nozzle.
The printing unit further receives the shift line data generated by the shift processing unit, and the received shift line data corresponds to each of the nozzle rows and is assigned to each ink ejection nozzle. Divided into data A shift line data division processing unit that generates and outputs shift line data is provided.
The buffer unit stores each division shift line data corresponding to each nozzle row output from the shift line data division processing unit, receives a detection signal from the object detection mechanism, and receives the detection signal. It is configured to sequentially output the divided shift line data corresponding to each nozzle row to the print control unit at a predetermined ejection timing corresponding to each nozzle row based on the time.
The print control unit receives the divided shift line data corresponding to each nozzle row from the buffer unit, and operates the ink ejection nozzles of the corresponding nozzle rows based on the received divided shift line data. It may be configured.

In the above aspect, the printer head includes at least two rows of nozzles arranged side by side along the reference transport path. That is, one nozzle row is arranged on the transport downstream side of the other nozzle row. In each nozzle row, the ink ejection nozzles constituting one nozzle array are displaced in a direction orthogonal to the reference transfer path with respect to each ink ejection nozzle constituting the other nozzle array, and the other nozzles It is arranged so as to be located between the ink ejection nozzles forming the row. The ink ejection nozzles of each nozzle row are located at regular intervals in the direction orthogonal to the reference transfer path as a whole. In this way, the ink ejection nozzles are regularly arranged.

According to the above aspect, shift line data in which the allocation relationship for the entire ink ejection nozzles constituting each nozzle row is shifted is generated by the shift processing unit, and the shift line data is generated by the shift line data division processing unit for each nozzle row. The divided shift line data corresponding to the above and divided into the data assigned to each ink ejection nozzle is generated. As described above, when the shift line data is generated, it is necessary to shift the allocation relationship with respect to the entire ink ejection nozzle, so that the processing speed is required. Therefore, this aspect is useful when a printing unit having a relatively high processing speed, that is, a central processing unit (CPU) is provided.

The present invention comprises a transport mechanism for transporting an object along a transport surface including a predetermined reference transport path.
An object detection mechanism that detects the object transported by the transfer mechanism,
A misalignment detection mechanism that detects a misalignment of the object from the reference transport path in the direction orthogonal to the reference transport path in the transport surface.
It is composed of a printing mechanism that prints on the surface of the object transported by the transport mechanism.
The misalignment detection mechanism
In the transport direction of the transport mechanism, it is arranged on the downstream side of the object detection mechanism, receives a detection signal from the target detection mechanism, and at a predetermined imaging timing with reference to the time when the detection signal is received. An imaging camera that captures the surface of an object detected by the object detection mechanism,
It is composed of a misalignment detection unit that processes an image captured by the imaging camera and detects the misalignment of the object from the reference transport path.
The printing mechanism
A printer head in which at least two rows of nozzles in which a plurality of ink ejection nozzles are arranged at regular intervals are provided at predetermined intervals, and the reference transport path is referred to downstream of the imaging camera in the transport direction. As a printer head, each of the nozzle rows is arranged so as to be orthogonal to the reference transport path, and forms a predetermined print area with reference to the reference transport path.
It consists of a printing unit that causes the printer head to perform printing operations.
In each nozzle row of the printer head, the ink ejection nozzles constituting one nozzle row are displaced in a direction orthogonal to the reference transfer path with respect to each ink ejection nozzle constituting the other nozzle row, and It is arranged so as to be located between the ink ejection nozzles constituting the other nozzle row, and the ink ejection nozzles of each nozzle row are configured to be positioned at regular intervals in a direction orthogonal to the reference transfer path as a whole. Has been
The printing unit
Printing data for printing on the surface of the object, which is print data composed of at least one line of line data in the raster direction assigned to each ink ejection nozzle constituting each nozzle row. The print data storage unit to be stored and
The print data is sequentially read from the print data storage unit for each line, and the read line data is divided into line data corresponding to each nozzle row and assigned to each ink ejection nozzle. A line data division processing unit that generates and outputs data, and
A division line data storage unit that stores division line data output from the line data division processing unit, and a division line data storage unit.
The misalignment information detected by the misalignment detection unit is received and processing is started, the division line data corresponding to each nozzle row is sequentially read from the division line data storage unit, and received from the misalignment detection unit. Based on the misalignment information, the divided shift line data in which at least one of the allocation relationship to the nozzle row and the allocation relationship to the ink ejection nozzle is changed according to the misalignment direction and the misalignment amount is generated. The output shift processing unit and
Each of the divided shift line data corresponding to each nozzle row output from the shift processing unit is stored, a detection signal is received from the object detection mechanism, and each of the above is based on the time when the detection signal is received. A buffer unit that sequentially outputs the divided shift line data corresponding to each nozzle row at a predetermined discharge timing corresponding to the nozzle row, and
It is composed of a print control unit that receives divided shift line data corresponding to each nozzle row from the buffer unit and operates the ink ejection nozzles of the corresponding nozzle rows based on the received divided shift line data. Related to printing equipment.

According to the printing apparatus according to the present invention, based on the misalignment information of the object detected by the misalignment detection unit, at least the nozzle row is assigned by the shift processing unit according to the misalignment direction and the misalignment amount. Divided shift line data in which either the relationship or the allocation relationship to the ink ejection nozzle is changed is generated, and the ink ejection nozzle is operated by the print control unit based on the divided shift line data. As a result, the ink ejection nozzle is operated based on the divided shift line data even when the object is transported in a state where the object is displaced in the direction orthogonal to the reference transport path with respect to the reference transport path. As a result, the line data before the shift process can be corrected so that the print position becomes appropriate. Therefore, it is possible to appropriately print the print information on the surface of the object with the center position as a reference.

Further, in the present invention, since the divided line data is generated and then the divided line data is shifted to generate the divided shift line data, each shift process of the divided line data corresponding to the nozzle train is performed in parallel. It can be executed and the processing speed can be improved.

In the present invention, the printer head may be one in which ink of the same color is supplied to all the ink ejection nozzles constituting each of the nozzle rows.

According to the above aspect, by using inks of the same color, the print color to be reproduced can be appropriately reproduced on the object even if the allocation relationship of the line data to the ink ejection nozzles is shifted by the displacement. can do.

According to the printing apparatus according to the present invention, information is appropriately printed on the surface of the object with reference to the center position even when the object is transported in a direction orthogonal to the reference transport path. It becomes possible to do.

It is a front view which shows the printing apparatus which concerns on one Embodiment and the reference embodiment of this invention. It is a block diagram which shows the structure of the printing part of the printing apparatus which concerns on a reference embodiment. It is a top view which shows the arrangement of each nozzle row in the printer head of FIG. It is an enlarged view of the part of the region A1 of FIG. 3, and is the top view which shows the arrangement of the ink ejection nozzle which constitutes each nozzle row. (A) is a diagram showing an example of an image of line data, and (b) is a diagram showing an example of an image of shift line data. (A) to (d) are diagrams showing an example of an image of divided shift line data corresponding to each nozzle row and assigned to each ink ejection nozzle. (A) is a plan view showing a print state on an object when the shift process is not executed, and (b) is a plan view showing a print state on the object when the shift process is executed. It is a block diagram which shows the structure of the printing part of the printing apparatus which concerns on this embodiment. (A) is a diagram showing an example of an image of line data, and (b) to (e) are diagrams showing an example of an image of divided line data corresponding to each nozzle row. (A) to (d) are diagrams showing an example of an image of divided shift line data corresponding to each nozzle row and assigned to each ink ejection nozzle, and (e) are diagrams (a) to (d). It is a figure which shows an example of the image of the line data when the division shift line data of is tentatively combined. It is a top view which shows that the object is conveyed as set in the conventional printing apparatus. It is a top view which shows that the object is carried by shifting the position in the conventional printing apparatus.

Hereinafter, specific embodiments of the present invention will be described with reference to the drawings.

( Reference embodiment)
First, a reference embodiment for the present invention will be described. As shown in FIG. 1, the printing apparatus 1 according to the reference embodiment has a supply mechanism 2 that aligns and supplies the objects T, and a predetermined reference transport path KH (FIG. 7 (a)) that supplies the supplied objects T. ), (B)) and the transfer surface 3a (see FIGS. 7 (a) and 7 (b)), and the rotary transfer mechanism 4 to which the object T is transferred from the transfer mechanism 3. An object detection mechanism 14 (see FIG. 2) having an object sensor 5, a rotary encoder 13 (see FIG. 2), and a timing generator 16 (see FIG. 2) to detect the position of the object T conveyed by the transfer mechanism 3. An object having an imaging camera 6 and a misalignment detection unit 17 (see FIG. 2) in a direction orthogonal to the reference transport path KH in the transport surface 3a, with reference to the reference transport path KH. A misalignment detection mechanism 19 (see FIG. 2) that detects a misalignment of T, a printer head 7 that prints on the surface of an object T transported by the transport mechanism 3, and printing that causes the printer head 7 to perform a printing operation. A printing mechanism 15 (see FIG. 2) having a portion 12 and a collecting mechanism 11 for collecting the printed object T are provided. Further, the printing device 1 includes an object sensor 8 having the same function as the object sensor 5, an imaging camera 9 having the same function as the imaging camera 6, and a print head 10 having the same function as the printer head 7. In the printing device 1 of the present embodiment, printing is executed by the printer head 7 on the surface of the object T conveyed by the conveying mechanism 3, and printing is executed on the surface of the object T conveyed by the rotary conveying mechanism 4. Printing is executed by the printer head 10 on the back surface of the object T. The shape of the object T is circular in a plan view. In the present invention, the method of printing on the back surface of the object T is the same as the method of printing on the front surface of the object T. Therefore, only the method of printing on the front surface of the object T will be described below.

The supply mechanism 2 includes a hopper 20 into which a large number of objects T are input, a vibration feeder 21 that applies vibration to the objects T discharged from the lower end of the hopper 20 to move them forward, and a terminal of the vibration feeder 21. A chute 22 that slides down the object T discharged from the chute, an alignment table 23 that rotates horizontally and aligns and discharges the object T supplied from the chute 22 in a row, and a disk-shaped member that rotates in a vertical plane. It is provided with a rotary transport body 24 that attracts and conveys the object T discharged from the alignment table 23 to the outer peripheral surface of the disk-shaped member. The object T, which is attracted and transported by the rotary transport body 24, is sequentially delivered to the transport mechanism 3.

The transport mechanism 3 includes a pair of transport belts (not shown) for transporting the object T, four transport belt pulleys (not shown) around which the transport belt is hung, and any one of the transport belts. It is equipped with a drive motor (not shown) for driving a pulley (not shown). The transport belt is an endless annular round belt arranged side by side at intervals in the width direction. The rotary encoder 13 (see FIG. 2) is attached to the drive motor.

The rotary transport mechanism 4 includes a rotary transport body 4a in which two transport belts (not shown) are wound around the outer peripheral surface. A suction force due to negative pressure is applied by the negative pressure mechanism on the transport belt wound around the rotary transport body 4a. In such a configuration, the object T is transported counterclockwise in FIG. 1 in a state of being attracted to the transport belt by the suction force. The object T is rotationally transported to the end point by the rotary transport mechanism 4, and then recovered by the recovery mechanism 11.

Subsequently, the configuration of the printer head 7 will be described. As shown in FIG. 1, the printer head 7 is arranged on the downstream side of the image pickup camera 6 in the transport direction D1. As shown in FIG. 3, the printer head 7 includes nozzle rows La, Lb, Lc, and Ld in which a plurality of ink ejection nozzles are arranged at regular intervals. The printer head 7 is arranged so that the nozzle trains La, Lb, Lc, and Ld are orthogonal to the reference transfer path KH with reference to the reference transfer path KH (see FIGS. 7A and 7B). That is, the nozzle rows La, Lb, Lc, and Ld are arranged along the direction D2 orthogonal to the transport direction D1 (hereinafter, referred to as the left-right direction). The nozzle rows La, Lc, Lb, and Ld are arranged in this order from the upstream side to the downstream side of the transport direction D1. The details of the arrangement of the ink ejection nozzles will be described later, but the width between the ink ejection nozzle Na1 located at the left end in the left-right direction D2 of the nozzle row La and the ink ejection nozzle Ndm located at the right end of the nozzle row Ld is The printable width RC (see FIGS. 7A and 7B). The printable width RC is set to be larger than the actual print width, which is the width at which printing is actually applied to the object T.

As shown in FIG. 4, the nozzle row La includes a plurality of ink ejection nozzles Na, the nozzle row Lb includes a plurality of ink ejection nozzles Nb, the nozzle row Lc includes a plurality of ink ejection nozzles Nc, and the nozzle row Ld includes a plurality of ink ejection nozzles Nc. It is provided with a plurality of ink ejection nozzles Nd. Regarding the ink ejection nozzles Na, those arranged in order from the left side to the right side in the left-right direction D2 are designated as Na1, Na2, Na3, Na4, ..., And those arranged at the right end are Nam (FIG. 5A). , (B)). The same numbering is applied to the ink ejection nozzles Nb, Nc, and Nd. In the present embodiment, ink of the same color (for example, black ink) is supplied from an ink tank (not shown) to all of the ink ejection nozzles Na, Nb, Nc, and Nd constituting the nozzle rows La, Lb, Lc, and Ld. To.

In each nozzle row, the ink ejection nozzles constituting one nozzle array are displaced in the left-right direction D2 with respect to each ink ejection nozzle constituting the other nozzle array, and each ink constituting the other nozzle array. It is arranged so as to be located between the discharge nozzles. In the example of FIG. 4, the ink ejection nozzles Na constituting the nozzle array La are arranged so as to be displaced in the left-right direction D2 with respect to each ink ejection nozzle Nc constituting the nozzle array Lc, and each ink ejection is performed. It is arranged so as to be located between the nozzles Nc. The same applies to the positional relationship between the ink ejection nozzle Na and the ink ejection nozzle Nb forming the nozzle row Lb, and the positional relationship between the ink ejection nozzle Na and the ink ejection nozzle Nd constituting the nozzle row Ld. In addition, the ink ejection nozzles of each nozzle row are arranged so as to be positioned at regular intervals in the left-right direction D2 as a whole. In the example of FIG. 4, the ink ejection nozzles Na of the nozzle row La are arranged at regular intervals in the left-right direction D2 as a whole. The same applies to the ink ejection nozzles Nb, Nc, and Nd.

In such a configuration, in the left-right direction D2, each ink ejection nozzle Nb is arranged on the right side of each ink ejection nozzle Na, and each ink ejection nozzle Nc is arranged on the right side of each ink ejection nozzle Nb. Each ink ejection nozzle Nd is arranged on the right side of each ink ejection nozzle Nc by one. In this way, the ink ejection nozzles Na, Nb, Nc, and Nd are arranged in a grid pattern. In FIG. 4, in order to facilitate understanding of the positional relationship of the ink ejection nozzles Na, Nb, Nc, and Nd, any one of the ink ejection nozzles Na1, Nb1, Nc1, and Nd1 extends along the transport direction D1. Four alternate long and short dash lines that pass through one are supplementarily added.

As shown in FIG. 2, the printing unit 12 of this example includes a print data storage unit 18, a shift processing unit 30, a shift line data division processing unit 31, a buffer unit 32, and a print control unit 33. These components are functionally realized by the central processing unit (CPU) provided in the printing device 1 executing a predetermined program stored in the memory.

The timing generation unit 16 calculates the position of the object T from the pulse signal output from the rotary encoder 13 and the detection signal of the object T output from the object sensor 5, and the timing of imaging with respect to the imaging camera 6. In addition to transmitting an imaging signal indicating, the buffer unit 32 transmits a print signal for causing the printer head 7 to execute printing to the buffer unit 32. The function of the buffer unit 32 will be described later.

Next, while explaining the configuration of the control system of the printing apparatus 1, a method of correcting the printing position when the object T is transported in a state of being displaced in the left-right direction D2 with reference to the reference transport path KH. explain.

As shown in FIG. 1, the image pickup camera 6 is arranged on the downstream side of the object sensor 5 in the transport direction D1. As shown in FIG. 2, the image pickup camera 6 receives the image pickup signal from the timing generation unit 16, and at a predetermined image pickup timing based on the time when the image pickup signal is received, that is, the object T is the object sensor 5. The surface of the object T is imaged at the timing when it enters the imaging field of view after a lapse of a predetermined time.

The misalignment detection unit 17 receives the imaged data from the image pickup camera 6, processes the image, and refers to the object T in the left-right direction D2 with reference to the reference transport path KH (see FIGS. 7A and 7B). Detects misalignment. For example, the misalignment detection unit 17 detects the center position of the object T, and provides information on how much (for example, how many pixels) the detected center position is misaligned in the left-right direction D2 (hereinafter, how many pixels). , Called misalignment information) is calculated and transmitted to the shift processing unit 30.

The print data storage unit 18 is data for printing print information on the object T, and is configured by collecting a plurality of rows of line data in the raster direction assigned to each ink ejection nozzle constituting each nozzle row. Print data is stored. As described above, the line data is data for forming one printing line (one line), and is a collection of dot data assigned to each ink ejection nozzle constituting the nozzle row. The line data is composed of, for example, 320 dot data.

The line data will be described with an example. As shown in FIG. 5A, the line data is data for forming one line of print information (for example, print information such as alphabets as shown in FIGS. 7A and 7B). In FIG. 5A, the black circles are dot data indicating instructions for ejecting ink, and the white circles are dot data representing instructions not for ejecting ink.

As shown in FIG. 5A, the line data is composed of a plurality of dot data assigned to each ink ejection nozzle in each nozzle row. As an example, the data D1 is assigned to the ink ejection nozzle Na1 located at the left end of the nozzle row La before the shift process described later. The data D2 is assigned to the ink ejection nozzle Nb1 located at the left end of the nozzle row Lb before the shift process described later. The data D3 is assigned to the ink ejection nozzle Nc1 located at the left end of the nozzle row Lc before the shift process described later. The data D4 is assigned to the ink ejection nozzle Nd1 located at the left end of the nozzle row Ld before the shift process described later. In addition, in FIGS. 5 and 6, the code of the ink ejection nozzle to which the data is assigned is shown below the black circle and the white circle representing each data. In the line data, data groups having the same numbering for each nozzle row are arranged in order from the left side to the right side in the figure in ascending order of numbering. The data D1, D2, D3, D4 shall belong to the data group G1, and the data D5, D6, D7, D8 shall belong to the data group G2, and so on. The data D1, D2, D3, D4 belonging to the data group G1 of FIG. 5A and the data Dn-3, Dn-2, Dn-1, Dn belonging to the data group Gi are obtained from the printable width RC of FIG. It corresponds to the margin width obtained by subtracting the actual print width. In the present embodiment, in order to facilitate understanding, the data corresponding to the margin width is set to four on the left side and four on the right side, respectively, but actually five or more (for example, about 40 to 50) are set. The data corresponding to the margin width is data indicating an instruction that ink should not be ejected.

Returning to FIG. 2, the shift processing unit 30 receives the position shift information from the position shift detection unit 17, and sequentially reads the print data from the print data storage unit 18 for each line, and from the read line data, the position shift information is obtained. The shift line data in which the allocation relationship with respect to the entire ink ejection nozzles constituting each nozzle row is shifted according to the misalignment direction and the misalignment amount is generated and transmitted to the shift line data division processing unit 31. This will be described in detail below.

Here, the misalignment information by the misalignment detection unit 17 is misaligned by the amount GA of the center position CP of the object T to the right side of the left-right direction D2 with reference to the reference transport path KH in FIG. 7A. The shift line data generated when the data is shown is described. For example, the misalignment amount GA is set to two pixels.

Although the details will be described later, when the shift processing by the shift processing unit 30 is executed, as shown in FIG. 7B, the object T is transported even when the object T is misaligned and conveyed. The print information (for example, the character information "TIPS") can be printed at the desired position above (that is, the position with reference to the center position CP of the object T). On the other hand, when the shift processing by the shift processing unit 30 is not executed, as shown in FIG. 7A, when the object T is transported with the position shifted to the right, it is on the object T. The print information is misaligned to the left from the desired position and printed. Actually, the misalignment amount GA in FIG. 7A corresponds to about 20 pixels, but it is set to 2 pixels for easy explanation.

In such a case, the shift processing unit 30 reads out the line data as shown in FIG. 5B in order to shift the allocation relationship to the ink ejection nozzle by the amount of misalignment GA with respect to the read line data. Shift line data is generated by adding empty data De1 and De2 for two pixels to the head portion of. As a result, the allocation relationship for each ink ejection nozzle is shifted to the right side in the raster direction by two pixels.

In the example of FIG. 5B, the data D1 assigned to the ink ejection nozzle Na1 before the shift processing is located on the right side of the ink ejection nozzle Na1 by two after the shift processing. Assigned to nozzle Nc1. Further, the data D2 assigned to the ink ejection nozzle Nb1 before the shift processing is assigned to the ink ejection nozzle Nd1 located on the right side of the ink ejection nozzle Nb1 by two after the shift processing. The allocation of other data is similarly shifted, and the data Dn-5 assigned to the ink ejection nozzle Ncm-1 located on the left side of the ink ejection nozzle Nam by two before the shift processing is transferred after the shift processing. Is assigned to the ink ejection nozzle Nam. Further, the data Dn-4 assigned to the ink ejection nozzle Ndm-1 located on the left side of the ink ejection nozzle Nbm by two before the shift processing is assigned to the ink ejection nozzle Nbm after the shift processing. Further, the data Dn-3 assigned to the ink ejection nozzle Nam located on the left side of the ink ejection nozzle Ncm by two before the shift processing is assigned to the ink ejection nozzle Ncm after the shift processing. Further, the data Dn-2 assigned to the ink ejection nozzle Nbm located on the left side of the ink ejection nozzle Ndm by two before the shift processing is assigned to the ink ejection nozzle Ndm after the shift processing. In addition, the shift processing unit 30 is accompanied by the shift processing, and the data for the last two pixels of the line data before the shift processing, that is, the data Dn− assigned to the ink ejection nozzles Ncm and Ndm before the shift processing. Delete 1 and Dn.

On the other hand, empty data De1 and De2 are assigned to the ink ejection nozzles Na1 and Nb1. Therefore, the ink is not ejected by these ink ejection nozzles Na1 and Nb1. In the above description, when the center position CP of the object T is displaced to the right side in the left-right direction D2 with respect to the reference transport path KH, an example in which the allocation relationship is shifted to the right side has been described. The same applies to the method of shifting the allocation relationship to the left when the center position CP of T is displaced to the left with respect to the reference transport path KH.

Next, the shift line data division processing unit 31 of FIG. 2 corresponds the received shift line data (that is, the shift line data of FIG. 5B) to each nozzle row and for each ink ejection nozzle. Generate split shift line data split for allocation. Then, the shift line data division processing unit 31 transmits the generated division shift line data to the buffer unit 32.

FIG. 6A shows an image of the divided shift line data assigned to each ink ejection nozzle Na of the nozzle row La, and FIG. 6B shows the divided shift line data assigned to each ink ejection nozzle Nb of the nozzle row Lb. An image is shown, FIG. 3C shows an image of division shift line data assigned to each ink ejection nozzle Nc of the nozzle row Lc, and FIG. 3D shows an image of division shift line data assigned to each ink ejection nozzle Nd of the nozzle row Ld. An image of shift line data is shown. As shown in FIG. 6A, the divided shift line data assigned to each ink ejection nozzle Na is an aggregate of the data De1 to Dn-5 assigned to the ink ejection nozzles Na1 to Nam in FIG. 5B. is there. Similarly, as shown in FIG. 6B, the divided shift line data assigned to each ink ejection nozzle Nb is the data De2 to Dn-4 assigned to the ink ejection nozzles Nb1 to Nbm in FIG. 5B. It is an aggregate. As shown in FIG. 6C, the divided shift line data assigned to each ink ejection nozzle Nc is an aggregate of data D1 to Dn-3 assigned to the ink ejection nozzles Nc1 to Ncm in FIG. 5B. is there. As shown in FIG. 6D, the divided shift line data assigned to each ink ejection nozzle Nd is an aggregate of the data D2 to Dn-2 assigned to the ink ejection nozzles Nd1 to Ndm in FIG. 5B. is there.

Subsequently, the buffer unit 32 of FIG. 2 stores each division shift line data output from the shift line data division processing unit 31. Then, the buffer unit 32 receives the above-mentioned print signal from the timing generation unit 16, and the division corresponding to each nozzle row at a predetermined discharge timing corresponding to each nozzle row based on the time when the print signal is received. The shift line data is sequentially output to the print control unit 33. In this case, the buffer unit 32 outputs the divided shift line data corresponding to the nozzle train La for one line based on the time when the print signal is received from the timing generation unit 16, and then at a predetermined timing after the output. The divided shift line data corresponding to the nozzle train Lc is output. Similarly, the buffer unit 32 outputs the divided shift line data corresponding to the nozzle row Lb at a predetermined timing after the output of the divided shift line data corresponding to the nozzle row Lc, and then outputs the divided shift line data corresponding to the nozzle row Lb, and then the nozzle row at a predetermined timing after the output. The split shift line data corresponding to Ld is output. The buffer unit 32 executes such processing for each line.

Next, the print control unit 33 receives the divided shift line data corresponding to each nozzle row from the buffer unit 32, and operates each ink ejection nozzle of each corresponding nozzle row based on the received divided shift line data. As a result, as shown in FIG. 7B, when the object T is transported in a state of being displaced in the left-right direction D2 with respect to the reference transport path KH, the printing position on the object T is moved to the right side. To be shifted. As a result, the misalignment of the print information as shown in FIG. 7A does not occur. When the data corresponding to an ink ejection nozzle having a certain nozzle row is black circle data (that is, data indicating an ink ejection instruction; see FIG. 6), the print control unit 33 inks from the ink ejection nozzle. The ink ejection nozzle is controlled to be opened so that the ink is ejected, and conversely, when the data is white circle data (that is, data indicating an ink non-ejection instruction, see FIG. 6), the ink ejection is performed. Control is performed to close the ink ejection nozzle so that the ink is not ejected from the nozzle.

As described above, in the printing apparatus 1 of this example , based on the misalignment information of the object T detected by the misalignment detection unit 17, the shift processing unit 30 determines the misalignment direction and the amount of the misalignment. Shift line data in which the allocation relationship to the ink ejection nozzle is shifted is generated, and the ink ejection nozzle is operated by the print control unit 33 based on the shift line data. As a result, even when the object T is transported in the left-right direction D2 with the reference transport path KH as a reference, the allocation relationship of the print data to the ink ejection nozzle is shifted by the misalignment. By operating the ink ejection nozzle based on the shift line data, it is possible to correct the line data before the shift process so that the print position becomes appropriate. This makes it possible to appropriately print print information on the surface of the object T with reference to the center position CP thereof.

Further, in this example , shift line data in which the allocation relationship with respect to the entire ink ejection nozzles constituting each nozzle row is shifted is generated by the shift processing unit 30, and the shift line data is generated by the shift line data division processing unit 31. It is configured so that the divided shift line data corresponding to each nozzle row and divided into the data assigned to each ink ejection nozzle is generated. As described above, when the shift line data is generated, it is necessary to shift the allocation relationship with respect to the entire ink ejection nozzle, so that the processing speed is required. Therefore, this aspect is useful when a printing unit 12 having a relatively high processing speed, that is, a central processing unit (CPU) is provided.

Further, in this example , ink of the same color (for example, black ink) is supplied to all of the ink ejection nozzles Na, Nb, Nc, and Nd constituting the nozzle rows La, Lb, Lc, and Ld. By using inks of the same color in this way, the print color to be reproduced can be reproduced on the object T even if the allocation relationship to the ink ejection nozzles in the line data is shifted as described above.

(Embodiment of the present invention )
Hereinafter, the printing apparatus according to the embodiment of the present invention will be described. As shown in FIG. 8, the configuration of the printing unit 12a of this example differs from the configuration of the printing unit 12 of the reference form (see FIG. 2) in that the line data is replaced with the shift line data dividing processing unit 31 of FIG. The point is that the division processing unit 34 is provided, the shift processing unit 30a is provided instead of the shift processing unit 30 in FIG. 2, and the division line data storage unit 35 is further provided. The printing unit 12a is functionally realized by the central processing unit (CPU) executing a predetermined program stored in the memory. Since the other configurations of FIG. 8 are the same as the configurations of FIG. 2, only the line data division processing unit 34, the division line data storage unit 35, and the shift processing unit 30a will be described below.

The line data division processing unit 34 sequentially reads print data from the print data storage unit 18 for each line, and divides the read line data into data corresponding to each nozzle row and assigned to each ink ejection nozzle. Generate split line data. In this case, the line data division processing unit 34 uses the line data of FIG. 9A (the same as the line data of FIG. 5A) for the division line data corresponding to the nozzle row La (FIG. 9B). (See), the division line data corresponding to the nozzle row Lb (see FIG. 9C), the division line data corresponding to the nozzle row Lc (see FIG. 9D), and the division line corresponding to the nozzle row Ld. It is divided into data (see FIG. 9E).

As shown in FIG. 9B, the division line data corresponding to each ink ejection nozzle Na is an aggregate of the data D1 to Dn-3 assigned to the ink ejection nozzles Na1 to Nam in FIG. 9A. .. Similarly, as shown in FIG. 9C, the division line data corresponding to each ink ejection nozzle Nb is a set of data D2 to Dn-2 assigned to the ink ejection nozzles Nb1 to Nbm in FIG. 9A. The body. As shown in FIG. 9D, the division line data corresponding to each ink ejection nozzle Nc is an aggregate of the data D3 to Dn-1 assigned to the ink ejection nozzles Nc1 to Ncm in FIG. 9A. .. As shown in FIG. 9E, the division line data corresponding to each ink ejection nozzle Nd is an aggregate of the data D4 to Dn assigned to the ink ejection nozzles Nd1 to Ndm in FIG. 9A. Such divided line data is composed of, for example, 80 dot data. The line data division processing unit 34 transmits the division line data to the division line data storage unit 35. The divided line data storage unit 35 stores the received divided line data.

The shift processing unit 30a receives the above-mentioned misalignment information from the misalignment detection unit 17 and sequentially reads out the division line data from the division line data storage unit 35 for each line, and the misalignment direction and the misalignment amount of the misalignment information In response to the above, the division shift line data in which at least one of the allocation relationship to the nozzle row and the allocation relationship to the ink ejection nozzle is changed is generated from the division line data and transmitted to the buffer unit 32. The details will be described below. In the following description, unless otherwise specified, the position shift information by the position shift detection unit 17 is left and right with respect to the reference transport path KH at the center position CP of the object T, as in FIG. 7 (a) above. It is premised that the position is shifted to the right side of the direction D2 by the amount of misalignment GA (2 pixels) , and those having the same reference numerals as the reference form have the same meaning.

Here, as described above in FIG. 4, in the printing apparatus 1, each ink ejection nozzle Nb is arranged on the right side of each ink ejection nozzle Na by one in the left-right direction D2, and one of each ink ejection nozzle Nb. Each ink ejection nozzle Nc is arranged on the right side, and each ink ejection nozzle Nd is arranged on the right side by one of each ink ejection nozzle Nc. In the present embodiment, by utilizing the positional relationship of the ink ejection nozzles Na, Nb, Nc, and Nd, it is possible to shift the print information to the right side by, for example, two pixels and print. The details will be described below.

Regarding the read divided line data, the shift processing unit 30a corresponds to each ink ejection nozzle Na of the nozzle row La before the shift processing according to the displacement amount GA (for 2 pixels) (FIG. 9 (b) divided line data) is shown on the right side of the ink ejection nozzle Na by two (two on the right side in the left-right direction D2; the same applies hereinafter). It is assigned to the nozzle train Lc composed of Nc. Therefore, in this case, only the allocation relationship to the nozzle row is changed. By changing the allocation relationship to the nozzle row in this way, the print information that was planned to be formed by the ink ejection nozzle Na is transferred to the ink located on the right side of the ink ejection nozzle Na by two after the shift process. It can be formed by the discharge nozzle Nc. This makes it possible to shift the printing on the object T to the right with respect to the ink ejection nozzle Nc.

Further, the shift processing unit 30a corresponds to each ink ejection nozzle Nb of the nozzle row Lb before the shift processing according to the displacement amount GA (2 pixels) (FIG. 9 (c)). The division line data) is assigned to the nozzle row Ld composed of the ink ejection nozzles Nd located on the right side of the ink ejection nozzles Nb by two as shown in FIG. 10D. Therefore, in this case as well, only the allocation relationship to the nozzle row is changed. By changing the allocation relationship to the nozzle row in this way, the print information that was planned to be formed by the ink ejection nozzle Nb is the ink that is located on the right side of the ink ejection nozzle Nb by two after the shift processing. It can be formed by the discharge nozzle Nd. As a result, it is possible to shift the printing on the object T to the right with respect to the ink ejection nozzle Nd.

Further, the shift processing unit 30a corresponds to each ink ejection nozzle Nc of the nozzle row Lc before the shift processing according to the misalignment amount GA (2 pixels) (FIG. 9D). The division line data) is assigned to the nozzle row La composed of the ink ejection nozzles Na located on the right side of the ink ejection nozzles Nc by two as shown in FIG. 10A. However, in this case, it is necessary to assign the division line data to the ink ejection nozzle Na located on the right side of the ink ejection nozzle Nc by two, that is, in the example of FIG. 9A, the ink ejection nozzle Since it is necessary to allocate the data D3 of Nc1 to the ink ejection nozzle Na2, the shift processing unit 30a allocates the empty data De1 to the ink ejection nozzle Na1 of FIG. 10A and deletes the data Dn-1. In this process, both the allocation relationship to the nozzle row and the allocation relationship to the ink ejection nozzle are changed.

In this way, the data assigned to any of the ink ejection nozzles corresponding to one data group (for example, the data group G1 in FIG. 9A) before the shift processing is jumped over the data group by the shift processing. When assigning to any ink ejection nozzle corresponding to another data group (for example, the data group G2 of FIG. 9A), at least one of the divided shift line data (in this example, in this example). One) of empty data is added and at least one (in this example, one) data is deleted based on the end. For example, when the data assigned to any of the ink ejection nozzles corresponding to the data group G1 is assigned to any of the ink ejection nozzles corresponding to the data group G3 by the shift process, the divided shift line data. In, two empty data are added and two data are deleted based on the end.

Further, the shift processing unit 30a corresponds to each ink ejection nozzle Nd of the nozzle row Ld before the shift processing according to the displacement amount GA (2 pixels) (FIG. 9 (e)). The division line data) is assigned to the nozzle row Lb composed of the ink ejection nozzles Nb located on the right side of the ink ejection nozzles Nd by two as shown in FIG. 10B. However, in this case, it is necessary to assign the division line data to the ink ejection nozzle Nb located on the right side of the ink ejection nozzle Nd by two, that is, in the example of FIG. 9A, the ink ejection nozzle Since it is necessary to allocate the data D4 of Nd1 to the ink ejection nozzle Nb2, the shift processing unit 30a allocates the empty data De2 to the ink ejection nozzle Nb1 of FIG. 10B and deletes the data Dn in the same manner as described above. Therefore, in this process as well, both the allocation relationship to the nozzle row and the allocation relationship to the ink ejection nozzle are changed. Note that FIG. 10 (e) shows an image of the line data when the divided shift line data of FIGS. 10 (a) to 10 (d) are tentatively combined, and the line data is the shift line data of FIG. 5 (b). It turns out that it is the same as. In the above description, an example in which the allocation relationship is changed when the center position CP of the object T is displaced to the right side in the left-right direction D2 with respect to the reference transport path KH has been described, but the center of the object T has been described. The same applies to the method of changing the allocation relationship when the position CP is displaced to the left with respect to the reference transport path KH.

Other examples will be described. In the same manner as above, when the displacement amount GA is, for example, one pixel, the division line data (division of FIG. 9B) corresponding to each ink ejection nozzle Na of the nozzle row La before the shift processing. The line data) is assigned to the nozzle row Lb composed of the ink ejection nozzles Nb located one right side of the ink ejection nozzle Na (one right side in the left-right direction D2; the same applies hereinafter). The division line data (division line data in FIG. 9C) corresponding to each ink ejection nozzle Nb of the nozzle row Lb before the shift processing is an ink ejection nozzle located on the right side of the ink ejection nozzle Nb by one. It is assigned to the nozzle train Lc composed of Nc. The division line data (division line data in FIG. 9D) corresponding to each ink ejection nozzle Nc of the nozzle row Lc before the shift processing is an ink ejection nozzle located on the right side of the ink ejection nozzle Nc by one. It is assigned to the nozzle train Ld composed of Nd. The division line data (division line data in FIG. 9E) corresponding to each ink ejection nozzle Nd of the nozzle row Ld before the shift processing is an ink ejection nozzle located on the right side of the ink ejection nozzle Nd by one. It is assigned to the nozzle train La composed of Na, one empty data is added to the divided shift line data, and the last data is deleted.

Further, when the misalignment amount GA is, for example, 3 pixels, the division line data (division line data in FIG. 9B) corresponding to each ink ejection nozzle Na of the nozzle row La before the shift processing is , It is assigned to the nozzle row Ld composed of the ink ejection nozzles Nd located on the right side of the ink ejection nozzle Na by three (three on the right side in the left-right direction D2; the same applies hereinafter). The division line data (division line data in FIG. 9C) corresponding to each ink ejection nozzle Nb of the nozzle row Lb before the shift processing is the ink ejection nozzle located on the right side of the ink ejection nozzle Nb by three. It is assigned to the nozzle train La composed of Na, one empty data is added to the divided shift line data, and the last data is deleted. The division line data (division line data in FIG. 9D) corresponding to each ink ejection nozzle Nc of the nozzle row Lc before the shift processing is the ink ejection nozzle located on the right side of the ink ejection nozzle Nc by three. It is assigned to the nozzle train Lb composed of Nb, one empty data is added to the divided shift line data, and the last data is deleted. The division line data (division line data in FIG. 9E) corresponding to each ink ejection nozzle Nd of the nozzle row Ld before the shift processing is the ink ejection nozzle located on the right side of the ink ejection nozzle Nd by three. It is assigned to the nozzle train Lc composed of Nc, one empty data is added to the divided shift line data, and the last data is deleted.

Further, when the misalignment amount GA is, for example, 4 pixels, it is not necessary to change the allocation relationship to the nozzle row, and empty data is set in each of the divided shift line data of FIGS. 10A to 10D. By adding and deleting the data at the end, only the allocation relationship to the ink ejection nozzle needs to be changed. That is, if the division line data corresponding to the nozzle row La shown in FIG. 9B is described as an example, the data D9 assigned to, for example, the ink ejection nozzle Na3 before the shift processing is ejected by the ink ejection processing. It is assigned to the ink ejection nozzle Na4 located on the right side of four nozzles Na3. As a result, the print information that was planned to be formed by the ink ejection nozzle Na3 can be formed by the ink ejection nozzle Na4 located on the right side of the ink ejection nozzle Na3 by four after the shift process. This makes it possible to shift the printing on the object T to the right with respect to the ink ejection nozzle Na. It should be noted that other data in the divided line data corresponding to the nozzle row La and each data in the divided line data corresponding to the nozzle rows Lb, Lc, Ld are similarly assigned by the shift process.

As described above, the misalignment amount GA (for example, for 4 pixels) is n times the total number of nozzle rows (4 in this embodiment) (n is a natural number, that is, 1, 2, 3, ...). In this case, only the allocation relationship to the ink ejection nozzle is changed by adding the n empty data to each divided shift line data and deleting the n data based on the end. On the other hand, when the misalignment amount GA is not n times the total number of nozzle rows (1 pixel, 2 pixels, 3 pixels, 5 pixels, 6 pixels, etc.), the allocation relationship to the nozzle rows And both the allocation relationship to the ink ejection nozzle are changed.

As described above, according to the present embodiment, based on the misalignment information of the object T detected by the misalignment detection unit 17, at least the nozzle row by the shift processing unit 30a according to the misalignment direction and the misalignment amount. The divided shift line data in which either the allocation relationship to the ink ejection nozzle or the ink ejection nozzle is changed is generated, and the ink ejection nozzle is operated by the print control unit 33 based on the divided shift line data. As a result, even when the object T is transported in the left-right direction D2 with the reference transport path KH as a reference, the ink ejection nozzle is operated based on the divided shift line data. The line data before the shift process can be corrected so that the print position becomes appropriate. This makes it possible to appropriately print print information on the surface of the object T with reference to the center position CP thereof.

Further, in the present invention, since the divided line data is generated and then the divided line data is shifted to generate the divided shift line data, each shift process of the divided line data corresponding to the nozzle train is performed in parallel. It can be executed and the processing speed can be improved.

Although the printing device 1 according to the present embodiment has been described above, the aspect of the printing device 1 is not limited to this, and the following modified examples can be applied.

In the above embodiment, printing is performed on both the front surface and the back surface of the object T, but the present invention is not limited to this, and printing is performed on either the front surface or the back surface of the object T. May be configured to execute.

Further, in the above embodiment, the printer head 7 is provided with four rows of nozzle rows La, Lb, Lc, and Ld, but the present invention is not limited to this, and at least one row of nozzle rows may be provided. ..

Further, in the above embodiment, the object T having a circular shape in a plan view is used, but the present invention is not limited to this, and an object T having a shape other than the circular shape may be used. In this case, the misalignment detection unit 17 may be configured to process the captured image to recognize the position of the center of gravity of the object T and calculate the misalignment information regarding the recognized center of gravity position.

Further, in the above embodiment, the ink ejection nozzles constituting one nozzle row are arranged so as to be located between the ink ejection nozzles constituting the other nozzle row, but the present invention is limited to this. Instead, the ink ejection nozzles forming one nozzle row and the ink ejection nozzles forming another nozzle row may be arranged so as to be located on one virtual line along the transport direction D1.

1 Printing device 3 Transport mechanism 3a Transport surface 5 Object sensor 6 Imaging camera 7 Printer head 12 Printing unit 12a Printing unit 14 Object detection mechanism 15 Printing mechanism 17 Misalignment detection unit 18 Print data storage unit 19 Misalignment detection mechanism 30 shift Processing unit 30a Shift processing unit 31 Shift line data division processing unit 32 Buffer unit 33 Print control unit 34 Line data division processing unit 35 Divided line data storage unit D1 Transport direction D2 Left and right direction KH Reference transport path RC Printable width (predetermined printing) region)
T object

Claims (2)

A transport mechanism that transports an object along a transport surface that includes a predetermined reference transport route,
An object detection mechanism that detects the object transported by the transfer mechanism,
A misalignment detection mechanism that detects a misalignment of the object from the reference transport path in the direction orthogonal to the reference transport path in the transport surface.
It is composed of a printing mechanism that prints on the surface of the object transported by the transport mechanism.
The misalignment detection mechanism
In the transport direction of the transport mechanism, it is arranged on the downstream side of the object detection mechanism, receives a detection signal from the target detection mechanism, and at a predetermined imaging timing with reference to the time when the detection signal is received. An imaging camera that captures the surface of an object detected by the object detection mechanism,
It is composed of a misalignment detection unit that processes an image captured by the imaging camera and detects the misalignment of the object from the reference transport path.
The printing mechanism
A printer head in which at least two rows of nozzles in which a plurality of ink ejection nozzles are arranged at regular intervals are provided at predetermined intervals, and the reference transport path is referred to downstream of the imaging camera in the transport direction. As a printer head, each of the nozzle rows is arranged so as to be orthogonal to the reference transport path, and forms a predetermined print area with reference to the reference transport path.
It consists of a printing unit that causes the printer head to perform printing operations.
In each nozzle row of the printer head, the ink ejection nozzles constituting one nozzle row are displaced in a direction orthogonal to the reference transfer path with respect to each ink ejection nozzle constituting the other nozzle row, and It is arranged so as to be located between the ink ejection nozzles constituting the other nozzle row, and the ink ejection nozzles of each nozzle row are configured to be positioned at regular intervals in a direction orthogonal to the reference transfer path as a whole. Has been
The printing unit
Printing data for printing on the surface of the object, which is print data composed of at least one line of line data in the raster direction assigned to each ink ejection nozzle constituting each nozzle row. The print data storage unit to be stored and
The print data is sequentially read from the print data storage unit for each line, and the read line data is divided into line data corresponding to each nozzle row and assigned to each ink ejection nozzle. A line data division processing unit that generates and outputs data, and
A division line data storage unit that stores division line data output from the line data division processing unit, and a division line data storage unit.
The misalignment information detected by the misalignment detection unit is received and processing is started, the division line data corresponding to each nozzle row is sequentially read from the division line data storage unit, and received from the misalignment detection unit. Based on the misalignment information, the divided shift line data in which at least one of the allocation relationship to the nozzle row and the allocation relationship to the ink ejection nozzle is changed according to the misalignment direction and the misalignment amount is generated. The output shift processing unit and
Each of the divided shift line data corresponding to each nozzle row output from the shift processing unit is stored, a detection signal is received from the object detection mechanism, and each of the above is based on the time when the detection signal is received. A buffer unit that sequentially outputs the divided shift line data corresponding to each nozzle row at a predetermined discharge timing corresponding to the nozzle row, and
It is composed of a print control unit that receives divided shift line data corresponding to each nozzle row from the buffer unit and operates the ink ejection nozzles of the corresponding nozzle rows based on the received divided shift line data. A printing device characterized by being Said printer head, the printing apparatus according to claim 1, wherein the all of the ink discharge nozzles constituting each nozzle row in which the same color ink is supplied.

Images